from Walking in Ireland
The Causeway Coaster shuttle bus offers service between the Visitor
Center and Giant's Causeway at 15-minute intervals. (As a walker, you'll
probably just wave at the bus as it goes by.)
Another bus, the Causeway Rambler, runs from Bushmills Distillery to
the Causeway Visitor Center, Dusverick Castle, White Park Bay, Ballintoy, and
the Carrick-a-Rede Rope Bridge from mid-June to mid-September.
For current details, see
and double-check specific route
timetables at Translink's Web site.